The objective of this project is the improvement of the quantitative evaluation of the cardiovascular status of patients with heart disease. The current methods for radiographic centriculometry oberestimate the volume of the heart, especially in systole. The error of overestimation becomes larger as the myocardial pathology becomes more severe. We propose to apply a new method (by Ahlberg) for the first time to clinical cases. Single plane cine left ventriculograms will be made. Measurements will be made on patients undergoing coronary arteriography before and after myocardial revascularization. Approximately 20% of our patients do not have coronary or myocardial disease, and they will serve as a control group. Left ventricular volumes will be determined by the new method of Ahlberg and by the classical method of Dodge and Sandler. End diastolic volume, end systolic volume, and stroke volume will be determined. Cardiac output obtained by the product of stroke volume and heart rate (if there is no regurgitation) will be compared with cardiac output measurements made by the dye dilution technique. The results will be compared to evaluate the relative precision and accuracy of the Ahlberg method versus the method of Dodge and Sandler. Depending on the results, the original calculations by Ahlberg will be modified to be adapted to clinical cases.